Weather patterns around the world are complex. One of the major influences on our weather is the ENSO (El Niño Southern Oscillation).
The El Niño Southern Oscillation (ENSO) is a natural climate cycle involving changes in ocean temperatures and atmospheric conditions in the tropical Pacific Ocean. It is split into three different phases – a neutral state, La Niña (a cooling state), and El Niño (a warming state). Of the three, it is El Niño that tends to make the headlines for the amount of disruption it can cause.
While every El Niño is different, the weather pattern can increase the risk of flooding in some regions and drought in others, affecting millions of people around the world. become exceptionally strong, known as super El Niño, with the potential for even more widespread impacts.
So what is El Niño? Is it linked to climate change? How does it impact people? And how can we prepare? Keep reading to learn more.
What is El Niño?
El Niño is a natural climate pattern that occurs when sea surface temperatures in parts of the Pacific Ocean become warmer than average. It is one phase of the El Niño Southern Oscillation (ENSO), a climate cycle that influences weather around the world.
Typically in the Pacific Ocean, water temperatures are higher in the west (around Australia and Asia) and cooler in the east (around the west coast of the Americas). The prevalent winds in the ocean also run from east to west. This is the ENSO in its neutral state.
In an El Niño event, the temperatures in the Pacific Ocean rise, particularly around the coast of South America. The prevailing winds across the Pacific also lessen, or in extreme cases, can be reversed. This can have a big effect on the world’s weather patterns. It can make some regions more prone to drought and heatwaves, while others are more likely to see severe storms and flooding.
Why is it called El Niño?
The name El Niño comes from Spanish and means ‘The Little Boy’ or ‘Christ Child’. Peruvian fishing communities noticed unusually warm ocean waters appearing around Christmas and called the phenomenon ‘El Niño de Navidad’. Scientists later adopted the name for the climate pattern we know today.
El Niño is a part of a fluctuating pattern of ocean temperatures in the Pacific. Its counterpart is La Niña (‘the girl’). This is when Pacific Ocean temperatures are cooler than average, also impacting world weather. Typically, both El Niño and La Niña events appear every two to seven years, with neutral periods in between. However, there is no set pattern, and anomalies do occur; for example, the winters of 2020 to 2022 were all La Niña events.
Both El Niño and La Niña events tend to last for 9 to 12 months, and their biggest impacts are typically felt in wintertime for the Northern Hemisphere.
Is El Niño linked to climate change?
El Niño is a natural climate pattern that has been part of Earth’s climate system for hundreds of years. Scientists are still studying how climate change may affect El Niño, and there is currently no clear evidence that global warming is directly causing El Niño events to become more frequent or intense.
While the link between climate change and El Niño remains uncertain, scientists agree that the impacts of El Niño can be amplified in a warmer world. Rising global temperatures mean El Niño events now occur against a warmer climate, which can contribute to more intense heat, heavier rainfall and more extreme weather conditions in some regions.
Although scientists cannot predict every impact with certainty, El Niño occurring alongside human-driven climate change can increase the risk of hazards such as floods, droughts, heatwaves, and wildfires, with significant consequences for communities around the world.
Does El Niño cause disasters?
El Niño can increase the likelihood of extreme weather in some parts of the world by disrupting normal rainfall and temperature patterns. Its impacts vary by region, but it can contribute to hazards such as flooding, drought, and severe storms.
El Niño flooding
El Niño often brings heavier rainfall to parts of South America, including Peru, as well as regions such as the Horn of Africa and parts of Central Asia. This increased rainfall can lead to flooding, landslides, and damage to homes and infrastructure.
ShelterBox has responded to flooding linked to El Niño, including in Paraguay in 2019, where high water levels forced families from their homes.
El Niño drought
While some areas become wetter, others can experience prolonged dry conditions. Australia, Indonesia, Central America and parts of southern Asia are often at greater risk of drought during El Niño events.
Reduced rainfall can affect crops, livestock and water supplies, increasing the risk of food insecurity and displacement.
El Niño storms
El Niño can also influence storm activity around the world. Some regions experience an increased risk of heavy rainfall and severe storms, while others may see drier-than-average conditions. Because El Niño affects weather patterns on a global scale, its impacts differ from place to place and from one event to the next.
When does a hazard become a disaster?
Hazards such as floods, storms and droughts do not automatically become disasters. Factors such as housing, infrastructure, living conditions and how well-prepared governments and authorities are to respond can all influence how severely communities are affected.
At ShelterBox, we avoid using the term ‘natural’ to describe a disaster for this reason. While El Niño is a natural climate pattern, we must not overlook the human, social, and economic factors that can turn a hazard into a disaster. Nor should we assume that the outcome is inevitable.
What are the effects of El Niño on people?
The impacts of El Niño can extend far beyond changes in the weather. When floods, droughts, and other hazards affect homes, livelihoods, and infrastructure, communities can face long-term challenges in recovering and rebuilding.
One of the biggest risks is food security. Changes in rainfall, temperatures, and ocean conditions can reduce crop yields, affect livestock, and disrupt fishing communities, leading to food shortages and rising prices.
El Niño can also affect health and displacement. Flooding, drought and other extreme weather events can force people from their homes, while some conditions can increase the spread of diseases such as malaria, dengue fever and cholera.
Find out more about how El Niño impacts communities around the world, from flooding in Malawi and Peru to drought and displacement in Somalia.
Why preparedness matters during El Niño
El Niño can increase the risk of flooding, drought and other extreme weather hazards in different parts of the world. While extreme weather cannot always be prevented, communities and humanitarian organizations can take steps to prepare.
Forecasts can help identify potential risks, allowing aid organizations to strengthen local partnerships, pre-position aid and develop response plans before disasters strike. This becomes even more important when different regions may face emergencies at the same time, creating more complex and overlapping humanitarian challenges.
Preparedness can also help organizations respond more quickly and efficiently when people lose their homes. By improving supply chains, expanding supplier networks and building relationships with local partners before a disaster happens, humanitarian organizations can be better positioned to support affected communities when they need it most.
At ShelterBox, our focus on localization and preparedness work in recent years has put us in a strong position to navigate these challenges. By continuing to establish and strengthen strong relationships with local partners and preposition aid in more key locations around the world, we will have the best chance of reaching people quickly when disaster strikes.
— Dave Raybould, Emergency Coordinator
How can ShelterBox help?
We believe that no one should be without shelter after a disaster.
We have supported people affected by El Niño-related flooding, including Lilian in Paraguay. In 2019, severe flooding forced Lilian, her husband, and their family to leave their home and move to a temporary settlement. Like many families living near the Paraguay River, they could not afford to move to a safer area.
ShelterBox provided solar lights, blankets, and a shelter kit to help the family cope while displaced and begin repairing their flood-damaged home. Lilian said the solar light helped her family feel safer when darkness fell in the temporary settlement.
While we cannot predict exactly how future El Niño events will unfold, we can be ready to support communities facing flooding, drought and other extreme weather hazards. With the support of our donors, partners and local networks, we can help people rebuild after disaster and recover more quickly when they lose their homes.
El Niño FAQs
El Niño affects different regions in different ways. Countries that have experienced significant impacts during past El Niño events include Peru, Ecuador, Indonesia, Australia, Ethiopia, and parts of Central America. However, every El Niño is different, and impacts can vary from one event to another.
Scientists can identify when El Niño conditions are developing, but predicting exactly where the most severe impacts will occur is much more challenging.
Each El Niño event is unique, with different effects on rainfall, temperatures, and weather patterns around the world.
El Niño and La Niña are opposite phases of the El Niño Southern Oscillation (ENSO). El Niño is associated with warmer-than-average sea surface temperatures in the Pacific Ocean, while La Niña occurs when those temperatures are cooler than average.
Both can influence weather patterns worldwide, but in different ways.
Yes. Changes in rainfall, temperatures, and ocean conditions can affect crops, livestock, and fisheries. This can reduce food production, increase prices, and make it harder for some communities to access the food they need.
Yes. Flooding, drought, and other extreme weather hazards associated with El Niño can damage homes, disrupt livelihoods, and force people to seek temporary shelter or relocate.
For communities already facing poverty, conflict, or the climate crisis, recovery can be particularly challenging.
Yes. El Niño can increase the likelihood of flooding in some parts of the world while contributing to drought in others.
This can create multiple humanitarian emergencies at the same time, increasing pressure on communities, governments, and humanitarian organizations.
El Niño leads to higher ocean temperatures, but it also creates stronger wind shear – a change in wind speed or direction – in the Caribbean and Atlantic. This wind shear can disrupt developing hurricanes, making it harder for Atlantic storms to form or strengthen.
As a result, forecasters often expect below-average Atlantic hurricane activity during El Niño years. However, there are still significant uncertainties, and a quieter season does not necessarily mean less destruction.
It only takes one hurricane making landfall to cause severe damage and displacement. That’s why preparedness remains just as important, even when hurricane activity is forecast to be below average.
El Niño can increase the likelihood of different hazards occurring in different regions at the same time. While some communities may experience flooding, others could face drought, heatwaves or food insecurity.
These overlapping crises can place additional pressure on humanitarian organizations, making preparedness, flexibility, and strong local partnerships increasingly important.